Survey And Test Of Insecticidal Activities Of Common Poisonous Plants In Tian Zhu Inartificial Meadow

1. There were 18 family, 24 genus and 62 species poisonous plants on the Tian Zhu grassplot.The abundant resourse of venomous plants privided the basic substance to the exploiture for the botanical pesticides.2. Aim at 10 kinds of poisonous plants process the identify of biological activity to extract. The results showed that 95% ethanol extracts of Ranunculus japonicus and 95% ethanol extracts of Euphorbia esula exhibited stomach poison activity against the Pieris rapae, when the concentration is 0.1g/mL,their final antifeedant rate were 90.67%,76.33% respectively in the time of 48h; their final adjusted mortality were 82.2%,77.3% in the time of 72h. Carbinol extracts of Aconitum gymnandrum showed the pesticidal activity against the Mythimna seperata, when the concentration is 0.1g/mL,its final antifeedant rate was 84.99% in the time of 48h; its final adjusted mortality was 74.5%in the time of 72h.3. To further research the biological activities of the plants which have shifted from 10 kinds poisonous plants .Using 4 impregant distilled the extracts from the R. japonicus,E. esula and A.gymnandrum and respectively determined the stomach poison toxicity, antifeedant activity,contact toxicity and diapause function .The results showed that the ethyl acetate extracts of R. japonicus,E. esula exhibited strong antifeedant activity,the average antifeedant rate were 85.4%,83.8% in the time of 48h at concentration of 0.2 g/mL,and showed strong stomach poison toxicity.with LC50 of 2.26 and 2.31g/L,respectively, however they had no contact toxicity to Pieris rapae.The test revealed that carbinol extract of A. gymnandrum manifested insecticidal activity to Mythimna seperata. The average antifeedant rate was 89.4% in the time of 48h at concentration of 0.2 g/mL,and showed strong stomach poison toxicity.with LC50 of 2.94 g/L.The extract of carbinol and ethanol of A.gymnandrum had contact toxicity to Mythimna seperata ,with LC50 of 3.22g/L,9.35g/L in the time of 72h.The extracts showed diapause function against Pieris rapae as well.After Pieris rapae was fed with the extract treated leaves,proteinase activity in midgust reduced with time increased.the weight of worm were declined and appeared the status of death. It was suggested that there have some elements which have the same polarity as ethyl acetate in Ranunculus japonicus and Euphorbia esula. 4. In order to further distilled the active components of the poisonous we adopted 2 means to distilled the three kinds of plants.the result showed that Sohxlet was better than cool soaking.